This proposal seeks funding to purchase a novel high-performance MR-compatible EEG device for high- density and real-time EEG/fMRI studies for the Athinoula A. Martinos Center for Biomedical Imaging. From among the commercially available EEG systems we have selected the one that would provide optimal SNR and allow for high-resolution EEG recording at MRI fields up to 3T. Concurrent EEG/fMRI provides high temporal and spatial resolution needed for clinical and translational research applications. For instance, the high SNR provided by the combination of these technologies will allow improved epileptogenic foci detection using single-event BOLD response; it will also enable monitoring of brain function during sleep, under anesthesia, and during image-guided surgeries for brain tumor. Combined EEG/fMRI wil also improve basic neuroscience research. In particular, the Instrument can be used to help determine how different areas of the human brain interact during information processing to elucidate inferring cortical feed-forward vs. feedback processes in the human brain. Furthermore, the instrument will allow studies of dynamic imaging of oscillatory brain networks controlling selective attention in auditory tasks. Additionally, this technology may shed light on the relation between hemodynamic and electrophysiological indices of error processing in behavioral response. Overall, this instrument will provide a unified computational and hardware framework for real-time concurrent EEG/fMRI measurements that can be used in both research studies and, eventually, clinical patient management. Hence, use of this system by our large and growing PHS-funded research community will have important implications for studies that aim to understand the interactions between electrical and BOLD signal in normal brain function, and how they change under pathological conditions such as epilepsy and schizophrenia, and under altered physiological states such as sleep and anesthesia. PUBLIC HEALTH RELEVANCE: The proposed EEG/fMRI system and related technologies will help understanding where and when pathological brain activity occurs in diseases such as epilepsy and Schizophrenia. This system will also enable brain monitoring under anesthesia, and for basic neuroscience studies.